Gyratory crusher mantle-bowl structure

ABSTRACT

Particularly formed telescopically mating conical elements (mantle and bowl) are disclosed for use in a cone type gyratory crusher as employed for reducing hard rock ore. Each of the conical elements includes a substantial crushing section of essentially linear taper, which has a hard metal surface layer (over 12 percent chromium and over 2.5 percent carbon) of at least 7/16-inch thickness. The two mating hard surfaces of the crusher elements (in offset concentric relationship) define an open truncated cone therebetween of variably gyrating thickness, the limits of which are substantially uniform. Above the open truncated cone, the mating elements define an enlarged, open feeding throat from which ore or other solid pieces are fed for crushing by the gyrating motion of the interior mantle element against the exterior bowl element. The relatively thick hard metal surface layers in cooperation with the linear shape of the conical crushing passage provides extended use periods for the crusher (wear being primarily abrasive) and effective crushing production.

United States Patent will n 27:",

[72] Inventor Donald Royce Gittings Fremont, Calif. [21] Appl.No.759,051 [22] Filed Sept.1l,l968 [45] Patented Feb.23,197l [73] AssigneeStoody Company [54] GYRATORY CRUSl-lER MANTLE-BOWL STRUCTURE 6 Claims, 3Drawing Figs.

[52] U.S.Cl 241/209; I

241/293;24l/299 [51] lnt.Cl B02c2/06 [50] FicldofSearch 241/207- [56]References Cited UNITED STATES PATENTS 575,549 1/1897 l-libbard 241/2932,097,709 11/1937 Walters 24l/293X 2,971,705 2/1961 Werner 24l/300X3,456 889 7/1969 Burkhardt 241/213 Primary ExaminerD0nald G. KellyAttorneyNilsson, Robbins, Wills & Berliner ABSTRACT: Particularly formedtelescopically mating conical elements (mantle and bowl) are disclosedfor use in a cone type gyratory crusher as employed for reducing hardrock ore. Each of the conical elements includes a substantial crushingsection of essentially linear taper, which has a hard metal surfacelayer (over 12 percent chromium and over 2.5 percent carbon) of at least7/ l 6-inch thickness. The two mating hard surfaces of the crusherelements (in offset concentric relationship) define an open truncatedcone therebetween of variably gyrating thickness, the limits of whichare substantially uniform. Above the open truncated cone, the matingelements define an enlarged, open feeding throat from which ore or othersolid pieces are fed for crushing by the gyrating motion of the interiormantle element against the exterior bowl element. The relatively thickhard metal surface layers in cooperation with the linear shape of theconical crushing passage provides extended use periods for the crusher(wear being primarily abrasive) and effective crushing production.

GYRATORY CRUSHER MANTLE-BOWL STRUCTURE BACKGROUND AND SUMMARY OF THEINVENTION Gyratory crushers are in widespread use, particularly topulverize hard rock ore prior to refining. In one common form, thesecrushers conventionally comprise a mantle of modified conical shapewhich is telescopically received within a mating bowl. The mantle isdriven in a gyrating pattern within the bowl so that ore (or the like)is crushed in passing through the opening-and-closing annular spacebetween these elements. Somewhat conventionally, the crusher elementsare made of Hadfield's Austinetic manganese alloys and are thereforequite expensive. As a result, various structural forms have beenproposed in the past with the objective of accomplishing a longer dutycycle before replacement is necessary. Specifically, for example, onecommon structure utilizes a bell-shape curve at the lower portion of themantle (so that it flares out-' ward from a regular conical shape) andamating bowl.

Although the tonnage production capability of crushers with such shapeshas been a matter of some question, the use of hard facing so as toreduce wear of the units has conventionally been resolved in thenegative. That is, the destructive forces within a gyratory crusherhaving a nonlinear taper, in the past have normally been considered tobe impact forces. As a result, hard facing at best has been restrictedto thin layers in order to avoid the spelling which is attendant impactforces. However, in accordance herewith, the provision of asubstantially true conical space between the crusher elements, resultsin destructive forces which are mostly abrasive, and, which thereforecan be resisted by a thick layer of hard facing on the crusher elements.Specifically, in accordance herewith, it has been determined that byproviding a layer of at least seven-sixteenths inch of hard metal on thecrushing surfaces of truly conical elements, major wear being primarilyfrom abrasive forces is well resisted.

Furthermore, as another consideration, it has been discovered that byproviding a substantially conical crushing space between the mantle andthe bowl or bowl liner structure, a large, effective feeding throat maybe provided so that wear in the conical section can be effectivelyadjusted without loss of production, by simply raising the mantle withreference to the mating bowl.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawing, which constitutes apart of this specification, an exemplary embodiment demonstratingvarious objectives and features hereof is set forth, specifically:

FIG. l is a perspective view of a gyratory crusher viewed in anoperating location;

FIG. 2 is a sectional and diagrammatic view taken vertically through thestructure as shown in FIG. 1;

FIG. 3 is an enlarged fragmentary view of the structure of FIG. 2further sectionalized to illustrate the detailed component structure.

DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENT Referring initially to FIG.1, there is shown a cone or gyratory crusher C set into the ground G assuch structures are commonly placed for reducing hard rock orespreliminary to further processing. Ore, or the like, is simply pouredinto the opening between the center hub and the rim 12 to pass throughthe crusher, emerging from the bottom in a reduced fine particle form.As better shown in FIG. 2, the rim 12 actually comprises the upperannular edge of a bowl 14 which is set in a supporting structure 16 (asmerely generally represented) so that trucks are provided access to dumpore into the crusher at the top from the level of the ground G.

The mating crushing element for the bowl 14 comprises a mantle ltlwhichmay be variously mounted as well known in the art so as to betelescopically received within the bowl 14. The mantle is supported atits upper end by an axial shaft 20 which is supportably received in thehub 10 affixed to the bowl 12 by brackets 22. The hub It) incorporatesbearing structure as well known, to accommodate gyratory motion by themantle 18.

At its lower end, the mantle 18 receives an offset or eccentric shaft 24which connects the mantle 18 to a gyratory drive unit 26. Various formsof this structure are widely employed which will drive the mantle 18 sothat it is moved in a somewhat orbital pattern crushing the ore as itfalls through a somewhat annular channel indicated by the dashed arrow28. It is to be noted, that in FIG. 2 the mantle 18 is shown centered orconcentric with respect to the bowl 14. However, it is to be understoodthat the motion of the mantle 18 is gyratory, and the depictedrelationship of the components is merely one transitory state.

Ore supplied to the annular passage between the mantle l8 and the bowl14, is initially received in a feeding" throat 30 in the form of anenlarged annular cavity downwardly tapered inwardly to meet the crushingspace. In the throat 30 the mantle 32 carries annular hard metal ridges32 while the mantle 18 carries similar ridges 34. These ridges tend toprotect the base metal casting comprising the bowl l4 and the mantle 18,form the destructive forces of large pieces of received ore.

Generally, the throat 30 in the bowl l4 converges to a small section 36then diverges over a portion 38 of substantially linear outward taper. Aportion 40 .on the mantle l8 tapers outwardly in a substantially linearmanner to mate with the portion 38 in opposing relationship. That is,both the portions 38 and 40 define an annular surface of substantiallyuniform linear taper and the two surfaces are in matingly facingrelationship. The shapes of these crushing members (defining the passagetherebetween, all cross sections of which extend in a single dimension)are a significant aspect of the present invention, in cooperation withthe layers of hard metal on the portions 38 and 40. The detailed aspectsof this structure will now be considered with reference to FIG. 3 toindicate the manner in which the system affords reduced wear as well asincreased production.

The shape of conventional prior conical crusher elements resulting fromwear and/or production is illustrated in FIG. 3 by basic castings forthe mantle 42 and the bowl 44. As illustrated these elements are shownto include sections 46 and 48 respectively, of buildup metal as well ashard metal sections 50 and 52 respectively. The manner in which suchadditional sections are applied and the component material thereof willbe considered in detail below. However, preliminarily, consider thecrusher as having the somewhat arcuate sectional surfaces of the mantle42 and the bowl 44 as defined by the lines 54 and 56 respectively.

As suggested above, it has been urged that by providing a bell shape forthe mantle (indicated by the line 56) wear in the crusher is reduced.However, in accordance herewith it has been determined that byeliminating such a bell shape to provide a linear or straight conicalpassage as in the form of truncated right circular cone, in conjunctionwith a hard facing surface of substantial thickness, wear is reduced andproduc tion is significantly increased. Furthermore, it is to be notedthat the conventional method of compensating for wear by moving themantle 42 upward with reference to the bowl 44 resulted in a problemwith nonlinearly flared elements. That is, as shown in FIG. 3, if themantle 42 is moved upwardly with reference to the bowl 44 (assumingthese members are formed as indicated by the lines 54 and 56) it may beseen that the operative crushing surfaces become of smaller and smallerarea and the throat 38 is capable of accommodating less volumeinhibiting choke-feeding operation. As a result, the efficiency of theapparatus is significantly reduced.

As indicated above, the mantle and bowl may be formed or worn to figuresof revolution which are defined in section as indicated by the dashedlines 54 and 56. In applying the present invention to reform orconstruct such units the por' tions 46 and 48 are initially added by theapplication of weld metal, utilizing well-known arc welding apparatus.It has been found desirable to provide the portions 46 and 48 by thedeposition of alternate layers 57 of nickel manganese alloy and layers59 of carbon-chrome steel. The utilization of the alternate materiallayers 57 and 59 on both the bowl and the mantle has been founddesirable to provide a firm base for the nickel manganese alloy and toallow the latter to work harden during actual use of the structure.

Of course, any of a wide variety of techniques may be employed todeposite the metal of the portions 46 and 48; however, in practiceapplications in layers of some 5/32-inch diameter have been found verysuccessful. in this regard, application has been accomplished byrotating the metal-receiving member in a holder as metal is deposited ina continuous bead about the circumferential surface. Submerged arctechniques have been found to be well suited for this purpose.

On completion of the portions 46 and 48, additional metal is applied toform the sections 50 and 52 which comprise hard metal defining a passage66 through the crusher. In this regard, it is to be noted that thesurface 60 of the section 52 and the surface 62 of the section 50 he incircular contact relationship. That is, these surfaces 60 and 62 mate asconcentric right circular cones, the mating tapers of each beingsubstantially linear. It is also to be noted that the sections 50 and 52are builtup to provide an increased cross-sectional size for the throat30 in relation to the passage 66. As a result, the crusher has a longerperiod of effective operation during which it may be choke fed" becausethe throat 30 may accommodate a relatively large volume of material eventhough the mantle 42 is raised to several different axial positions withregard to the bowl 44 (adjusting wear).

It is also to be noted that the shape of the section 52, defines adownstream" edge 68 at a substantial taper with the further objective ofavoiding the development of a flare or bell shape for the mantle 42 asdescribed above with wear and use of the crusher.

As indicated above, the particular shape of the mating mantle and bowlelements has been determined to be significant with regard to thedeposition of hard facing in a layer of at least 7/l6-inch thickness.That is, the sections 50 and 52 comprise hard facing metal and are wellin excess of inch thickness (somewhat critical for effective wearresistance). In this regard the application of hard facing metal (over2.5 percent carbon and over 12 percent chromium) in thickness over evenone-quarter of an inch to gyratory crushers have generally resulted inspalling. That is, the formative shape of prior crushers of the typehere considered have generally been considered to involve destructiveimpact forces which will comprise a chromium steel with at least 2.5percent carbon and 12 percent chrome, while the layers 72 comprisechromium steel including at least 4 percent carbon and 30 percentchrome. Each layer is deposited in acontinuous bead of arc welded metal,as by revolving the entire structure past a welding unit as well knownin the prior art.

The system hereof as indicated above, may be effectively employed tomanufacture or rebuild conical or gyratory crushers with mating linearlytapered surfaces comprising a substantial final layer of hard metal toresist resulting abrasive forces. Various forms hereof may be developedutilizing various techniques although the specific structure describedherein has been determined to be effective. Thus, the scope hereof isdefined by the appended claims.

lclaim:

1. An improved mating mantle-bowl structure for a crusher wherein adrive unit provides a gyratory movement between said mantle-bowlstructure to afford a crushing action, coma m antle defined as a figureof revolution and including an externally defined conical section ofsubstantially linear external taper and an external throat portionthereabove, said mantle comprising a base metal casting with an externalsurface layer extending over said externally defined conical sectioncomprising a hard metal in relation to said base metal and being of atleast seven-sixteenths of an inch in thickness; and

a bowl member for telescopically receiving said mantle, said bowl memberincluding an internally defined conical section of substantially linearinternal taper to mate with said externally defined conical section ofsaid mantle, and further including an external throat portion above saidinternally defined conical section, said bowl member comprising a basemetal casting with an internal surface layer extending over saidinternally defined conical section, said internal surface layercomprising a hard metal in relation to said base metal and being of atleast seven-sixteenths of an inch in thickness.

2. A structure according to claim 1 wherein said layers of hard metalare arc weld deposited.

3. A structure according to claim 1 wherein said mantle and bowl membersdefine a substantially enlarged annular feeding throat above saidsections of linear taper.

4. A structure according to claim 1 wherein said surface layers comprisea plurality of layers of weld metal of different individual hardness.

5. A structure according to claim 1 wherein said surface layers comprisea hard metal component layer having a carbon content over 3 percent anda chrome content over 20 percent.

6. A structure according to claim 1 wherein said surface layers comprisea plurality of layers of weld metal of different individual hardness andinclude a hard metal component layer having a carbon content over 3percent and a chrome content over 20 percent.

1. An improved mating mantle-bowl structure for a crusher wherein adrive unit provides a gyratory movement between said mantle-bowlstructure to afford a crushing action, comprising: a mantle defined as afigure of revolution and including an externally defined conical sectionof substantially linear external taper and an external throat portionthereabove, said mantle comprising a base metal casting with an externalsurface layer extending over said externally defined conical sectioncomprising a hard metal in relation to said base metal and being of atleast seven-sixteenths of an inch in thickness; and a bowl member fortelescopically receiving said mantle, said bowl member including aninternally defined conical section of substantially linear internaltaper to mate with said externally defined conical section of saidmantle, and further including an external throat portion above saidinternally defined conical section, said bowl member comprising a basemetal casting with an internal surface layer extending over saidinternally defined conical section, said internal surface layercomprising a hard metal in relation to said base metal and being of atleast seven-sixteenths of an inch in thickness.
 2. A structure accordingto claim 1 wherein said layers of hard metal are arc weld deposited. 3.A structure according to claim 1 wherein said mantle and bowl membersdefine a substantially enlarged annular feeding throat above saidsections of linear taper.
 4. A structure according to claim 1 whereinsaid surface layers comprise a plurality of layers of weld metal ofdifferent individual hardness.
 5. A structure according to claim 1wherein said surface layers comprise a hard metal component layer havinga carbon content over 3 percent and a chrome content over 20 percent. 6.A structure according to claim 1 wherein said surface layers comprise aplurality of layers of weld metal of different individual hardness andinclude a hard metal component layer having a carbon content over 3percent and a chrome content over 20 percent.